Watford ace Joshua is deep in camp for his March 31 unification battle with WBO king Joseph Parker so is unlikely to take up the offer, with three belts on the line in Cardiff.

Fury used an Instagram video to say: “I challenge AJ - Anthony Joshua - as a sporting challenge for charity of our choices £1000 sterling winner takes all for their choice of charity to a 2000 metres concept two rowing challenge.

“I would say I’m a better athlete than you Anthony and I’m willing to prove it, 2000 metres which is your usual distance for a race - concept two indoor rowing challenge.

“You and me - one on one - Sport Relief 2018. The challenge is out there - the ball’s in your court.”